Add 64 bit Linux Client building

Also re-labels most of the 32 bit client as such. The update channel was
left as just "lin" instead of "lin32" for compatibility reasons.

Signed-off-by: Thomas Berezansky <tsbere@mvlc.org>
Signed-off-by: Ben Shum <bshum@biblio.org>
Signed-off-by: Bill Erickson <berick@esilibrary.com>
Update make_release script for Linux 64 building

Signed-off-by: Thomas Berezansky <tsbere@mvlc.org>
Signed-off-by: Ben Shum <bshum@biblio.org>
Signed-off-by: Bill Erickson <berick@esilibrary.com>